import java.util.*;

public class Main {

    public static void main(String[] args) {
        Scanner input = new Scanner(System.in);

        int n = input.nextInt();
        int[] happy = new int[n + 1];
        List<Integer>[] tree = new ArrayList[n + 1];
        Arrays.setAll(tree, e -> new ArrayList<Integer>());

        for (int i = 1; i <= n; i++) {
            happy[i] = input.nextInt();
        }

        boolean[] vis = new boolean[n + 1];
        for (int i = 1; i < n; i++) {
            // y 是 x 的上司
            int x = input.nextInt();
            int y = input.nextInt();

            tree[y].add(x);
            vis[x] = true;
        }

        // 找 root
        int root = 0;
        for (int i = 1; i <= n; i++) {
            if (!vis[i]) {
                root = i;
                break;
            }
        }

        int[][] dp = new int[n + 1][2];
        dfs(root, tree, happy, dp);
        System.out.println(Math.max(dp[root][0], dp[root][1]));
    }

    private static void dfs(int node, List<Integer>[] tree, int[] happy, int[][] dp) {
        dp[node][1] = happy[node];
        for (Integer next : tree[node]) {
            dfs(next, tree, happy, dp);

            dp[node][0] += Math.max(dp[next][0], dp[next][1]);
            dp[node][1] += dp[next][0];
        }
    }

}